Reactive gases are used in many process steps in the fabrication of microelectronic components, optical components, analytical instruments, and other specialized equipment. Most of these reactive gases are highly hazardous to operating personnel, and the manufacture, storage, transportation, and end use of these gases must be carried out under strict safety procedures. These gases are transported and stored at ambient temperatures in pressurized cylinders either as compressed gases or as pressurized saturated liquids. The pressurized cylinders may be individual standalone cylinders or may be multiple-tube bundles used in tube trailers or ISO containers.
Each storage cylinder is fabricated with at least one discharge port, and the port typically is threaded for the installation of fluid flow fittings such as shutoff valves, bull plugs, and other fittings that are connected in turn to valve and piping s that supply gas to an end user. Leaks may occur in a fluid flow fitting at threaded connections, compression fittings, O-ring seals, valve stem packings, and valve seats. In many cases, these leaks are small (e.g., less than about 50 sccm), but even small leaks can be hazardous and may develop into larger and possibly catastrophic leaks. If leaks occur at an operating plant in which the cylinders are filled, appropriate safety equipment and procedures will be available to contain the leak and repair the leaking components. If leaks occur during cylinder transportation or while a cylinder is stored at a user's site, however, appropriate equipment and procedures to contain the leak and repair the leaking components may not be available.
There is a need in the art for methods of containing such leaks during cylinder transportation and storage in the time period between initial leak detection and the return of the leaking cylinder to a properly-equipped repair facility. This need is addressed by the embodiments of the invention described below and defined by the claims that follow.